whitesps = ' \r\n\v\f\t'

def rmrsps(astr):
    for i in range(-1,-len(astr),-1):  #自右向左，下示为负
        if astr[i] not in whitesps:
            return astr[:i + 1] #结束下标对应的字符不包含，所以加1
    else:
        return ''

if __name__== '__main__':
    print(rmrsps(''))
    print(rmrsps('  \thello  '))